Effect of reactant gas flow orientation on the current and temperature distribution in self-heating polymer electrolyte fuel cells

Fuel cell polarisation performance is typically reported under controlled/constant temperature conditions, as a sign of robust metrology. However, in practice, fuel cells self-heat as they generate current; which varies the temperature across the polarisation curve and affects performance. More detail regarding the internal cell operation can be gleaned by current and temperature distribution mapping. For the case of an unheated cell, ‘self-heating’ increases the cell temperature and improves performance, resulting in a ‘voltage recovery’ and a more homogeneous current and water distribution. For actively heated cells, a reduced current is observed in regions of high temperature and low humidity. The positioning of the gas manifolds also has a decisive impact on performance by affecting the reactant concentration, humidity and water distribution. Counter- and cross-flow orientations in a self-heating cell were studied, with a counter-flow orientation with air flowing with gravity producing the most uniform temperature distribution

Green Hydrogen Market and Technology Insight : Utilizing Existing Data to Develop Strategic Approach for LV Product Manufacturers

Green hydrogen has appeared as a promising alternative to fossil fuels in the decarbonization process because of the pursuit of sustainable energy solutions. This master’s thesis focuses on its application in carbon-neutral power generation using fuel cells. Where green hydrogen is positioned as an answer to the challenge of storing abundant renewable energy for extended periods. The primary objective is to investigate the green hydrogen market, focusing on electrolyser and fuel cell technologies. Further, investigate the factors influencing the efficiency of these components and explore academic case studies and real-world scenarios. The study aims to develop a strategic approach to understand market dynamics and technology requirements. This thesis was conducted for ABB Oy, Smart Power’s Solar, ESS, and H2 development application team. Comprehensive understanding arose with the exponential growth of the green hydrogen market intertwined with the advancement of renewable energy. This study extensively explores electrolyser and fuel cell technology and finds key challenges impacting the overall performance of the solution. Renewable energy cost is known as the significant factor driving the cost of the solution, study emphasizes the vital role of the efficiency of the system in controlling the cost. Furthermore, a market study is conducted in this work to identify the growth trends of the green hydrogen sector. The market study provides a brief navigator for LV product manufacture in this evolving landscape. The technological maturity is explored of electrolyser and fuel cell technologies efficiency in P2G-G2P solution. An extensive review of academic case studies and real-world scenarios scrutinizes the impact of efficiency on P2G-G2P. This found the critical gap between academic studies and industrial implementations. Therefore, a strategic approach was developed based on limitations in knowledge and insights from stakeholders. As the tool to collect valuable information, the questionnaire is presented with a specific focus on technology, efficiency, market status, and LV product specifications. This tool will serve to support product manufacturers to adapt to technical and market changes. To conclude, this master’s thesis contributes to the understanding of green hydrogen energy technology and guides LV product manufacturers in transitioning to sustainable future

Model Based Automotive System Integration: Fuel Cell Vehicle Hardware-In-The-Loop

abstract: Over the past decade, proton exchange membrane fuel cells have gained much momentum due to their environmental advantages and commutability over internal combustion engines. To carefully study the dynamic behavior of the fuel cells, a dynamic test stand to validate their performance is necessary. Much attention has been given to HiL (Hardware-in-loop) testing of the fuel cells, where the simulated FC model is replaced by a real hardware. This thesis presents an economical approach for closed loop HiL testing of PEM fuel cell. After evaluating the performance of the standalone fuel cell system, a fuel cell hybrid electric vehicle model was developed by incorporating a battery system. The FCHEV was tested with two different control strategies, viz. load following and thermostatic. The study was done to determine the dynamic behavior of the FC when exposed to real-world drive cycles. Different parameters associated with the efficiency of the fuel cell were monitored. An electronic DC load was used to draw current from the FC. The DC load was controlled in real time with a NI PXIe-1071 controller chassis incorporated with NI PXI-6722 and NI PXIe-6341 controllers. The closed loop feedback was obtained with the temperatures from two surface mount thermocouples on the FC. The temperature of these thermocouples follows the curve of the FC core temperature, which is measured with a thermocouple located inside the fuel cell system. This indicates successful implementation of the closed loop feedback. The results show that the FC was able to satisfy the required power when continuous shifting load was present, but there was a discrepancy between the power requirements at times of peak acceleration and also at constant loads when ran for a longer time. It has also been found that further research is required to fully understand the transient behavior of the fuel cell temperature distribution in relation to their use in automotive industry. In the experimental runs involving the FCHEV model with different control strategies, it was noticed that the fuel cell response to transient loads improved and the hydrogen consumption of the fuel cell drastically decreased.Dissertation/ThesisMasters Thesis Engineering 201

Solid oxide fuel cell: an overview

This paper will review the area of interest in fuel cell, especially in solid oxide fuel cell (SOFC). This area of interest covers SOFC operational reaction, its advantages and limitations, type of cell structure and configuration, and the requirement of SOFC. The review also looks into the development and fabrication of a research towards low temperature SOFC. There is also a review made by professional organizations that contribute to the research on fuel cell both locally and globally

Final Report - Advanced MEA's for Enhanced Operating Conditions, Amenable to High Volume Manufacture

This report summarizes the work completed under a 3M/DOE contract directed at advancing the key fuel cell (FC) components most critical for overcoming the polymer electrolyte membrane fuel cell (PEMFC) performance, durability & cost barriers. This contract focused on the development of advanced ion exchange membranes & electrocatalysts for PEMFCs that will enable operation under ever more demanding automotive operating conditions & the use high volume compatible processes for their manufacture. Higher performing & more durable electrocatalysts must be developed for PEMFCs to meet the power density & lifetime hours required for FC vehicles. At the same time the amount of expensive Pt catalyst must be reduced to lower the MEA costs. While these two properties are met, the catalyst must be made resistant to multiple degradation mechanisms to reach necessary operating lifetimes. In this report, we present the work focused on the development of a completely new approach to PEMFC electrocatalyts, called nanostructured thin film (NSTF) catalysts. The carbon black supports are eliminated with this new approach which eliminates the carbon corrosion issue. The thin film nature of the catalyst significantly improves its robustness against dissolution & grain growth, preserving the surface area. Also, the activity of the NSTF for oxygen reduction is improved by over 500% compared to dispersed Pt catalyts. Finally, the process for fabricating the NSTF catalysts is consistent with high volume roll-good manufacturing & extremely flexible towards the introduction of new catalyst compositions & structures. This report documents the work done to develop new multi-element NSTF catalysts with properties that exceed pure Pt, that are optimized for use with the membranes discussed below, & advance the state-of-the-art towards meeting the DOE 2010 targets for PEMFC electrocatalysts. The work completed advances the understanding of the NSTF catalyst technology, identifies new NSTF-ternary catalyst materials for higher performance, documents enhanced durability under multiple types of accelerated tests by factors of 10x to 50x over conventional catalysts, & demonstrates their performance & durability in large area MEA FC stack tests. The PEMFC ion exchange membrane is the other key functioning FC component on which work was completed. While improvements have been made to standard PFSA type membranes, they still require humidification to achieve adequate proton conductivity & so their use at elevated temperatures & drier operating conditions is limited. Membranes with increased durability & conductivity under hotter, drier conditions allow the use of FC's in many applications, particularly automotive. Towards this goal, 2 approaches were pursued in the work reported here. The first part was designed for immediate application at drier conditions & operating temperatures between 85C and 120C, focused on the development of a membrane based on a low equivalent weight (EW), perfluorinated sulfonic acid (PFSA) ionomer for good ionic conductivity at low humidification, & the use of stabilizing additives for improved oxidative stability. The ionomer used was developed at 3M & has a shorter acid containing side-chain than the Nafion™ ionomer. This ionomer also has a higher Tα & higher modulus than that of a Nafion™ membrane of the same EW, allowing lower EW ionomers to be prepared with very good mechanical properties. In addition, more than 50 stabilizing additives were evaluated in ex-situ, Fenton’s tests & more than 10 of these were incorporated into membranes & evaluated in accelerated FC tests. This work led to thin (25-30 micron) cast membranes with substantially improved conductivity & durability under simulated automotive conditions, compared to membranes currently available. The 2nd body of membrane work was focused on developing & characterizing 3 approaches for making new PEM's for operation under hot (>120C) & dry (dew point <80C) FC conditions: inorganic materials with enhanced proton conductivity, polymer matrices swollen with low molecular weight fluorinated acids & proton conducting ionic liquids. New materials developed show the promise of the development of new membranes with even better characteristics under demanding FC operating conditions, further improving the efficiency & viability of FC systems